Home networks are becoming more common and desirable for connecting computers within a home. One type of home network is the home phone line network which uses telephone lines typically installed in residential homes for communication between computers in the home. The Home Phone Line Networking Alliance (HPNA) has published a specification to standardize the behavior of home phone line networks.
FIG. 1 illustrates a home phone line network in accordance with the present invention. The preferred embodiment of the network complies with the Home Phoneline Networking Alliance specification version 2.0 (HPNA 2.0). The network allows multiple computers to communicate through telephone wires typically installed in residential homes. The HPNA network 116 communicates with a HPNA controller 100. The HPNA controller 100 comprises a Media Independent Interface (MII) 106, a Media Access Control (MAC) 108, and a Physical Layer (PHY) 110. The HPNA controller 100 implements the HPNA 2.0 specification. The HPNA controller 100 receives HPNA data frames from the HPNA network 116 through the telephone wires via a phone jack 102. There is an analog front end (AFE) 104 which processes the signal between the HPNA controller 100 and the HPNA network 116. The HPNA controller 100 then processes the HPNA data frames received in the signal from the AFE 104, and outputs a signal to a Host 112, which has a driver 118 for the HPNA controller 100, through an Ethernet controller 114.
FIG. 2 illustrates a structure of a HPNA data frame according to the HPNA 2.0. The HPNA data frame structure 240 comprises a 16-byte preamble field 218, a 4-byte frame control field 220, a 6-byte destination address field 222, a 6-byte source address field 224, a 2-byte Ethernet type field 226, a variable length Ethernet data field 228, a 4-byte Frame Check Sequence field (FCS) 230, a 2-byte Cyclic Redundancy Check field (CRC) 232, a 2-byte PAD field 234, and an 1-byte End Of Frame field (EOF) 236. According to the HPNA 2.0, the Host 112 must pass extra control information that is not present in a conventional Ethernet data frame 238. Similarly, the HPNA controller 100 must pass to the Host 112 extra frame control and status information that is not present in the conventional Ethernet data frame 238. The control information is contained in the frame control field 220. The HPNA data frame structure 240 is equivalent to a structure of the conventional Ethernet data frame 238 encapsulated within additional information, including the control information in the frame control field 220.
The control information includes priority and payload encoding. Priority information refers to the priority given to the HPNA data frame when determining media access. Payload encoding refers to codes for Baud rates and carrier frequencies to be used for data frame transmission.
However, when sending data frames to the Host 112 via the Ethernet controller 114, the Ethernet controller 114 can only process frames with the Ethernet data frame structure 238 and is not able to process the additional control information in a HPNA data frame structure 240. Additional wires can be installed between the Ethernet controller 114 and the HPNA controller 100 and between the Ethernet controller 114 and the Host 112 for transmission of the additional control information with special interfaces to handle the data transmission on these wires. However, this solution may be impractical.
Accordingly, there exists a need for a method for providing control information between a host and a HPNA network via an Ethernet controller. The method should not require additional wires or special interfaces. The present invention addresses such a need.